<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>jQuery鼠标事件之focusin事件</title>
	<script src="http://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
	<script>
		$(document).ready(function() {
			$("input").focusin(function() {
				$(this).css("border","1px solid red");
			});
		});
	</script>
	<style>
		* {
			margin:0;
			padding:0;
		}

		div {
			width:100px;
			height:50px;
			background: red;
		}
	</style>
</head>
<body>
	<div>
		<input type="text" name="" id="">
	</div>
</body>
</html>